Ruby Set Intersection

I have all the required methods but i m unsure of how to write intersection union and subset methods.

Ruby set intersection. The syntax is similar in both so don t worry about having to learn lots of different things. Additional speedup comes from using each instead of do with enum. And returns the common of the two arrays. I will cover arrays first because this is one of the most common objects found.

For intersection and union my code starts like this. Def intersect var x multiset new end here is an example. In the first form if no arguments are sent the new array will be empty. If you have zero interest to the intersection itself i think you can avoid creating the temporary array.

Returns a new array. The set is an unordered collection with no duplicate items. Array is a array class method which performs set intersection operation on the arrays. The second form creates a copy of the array passed as a parameter the array is generated by calling to ary on the parameter.

Set is easy to use with enumerable objects implementing each most of the initializer methods and binary operators accept generic enumerable objects besides sets and arrays. 2 3 this gives you the elements common in both sets. Check which pieces of equipment iron man has from a fixed list. Ruby array intersection operation last updated.

Arrays for performing the intersection operation. A superset is a set that contains all the elements of another set. X 1 1 2 4 y 1 2 2 2 then the intersection of x and y is 1 2. Intersect two arrays returning values that occur in both of them as a set an array with distinct values.

There are a couple of ways you can do intersections in ruby ruby i will talk you through both of them. Set intersection with arrays in ruby. It can be reduced to o s1 size s2 size min time. And here s the set intersection operator.

These 3 operators union difference intersection can also be used with arrays. 2 ruby core 89287 updated by c4am95 travis hunter almost 2 years ago. Common elements from both the arrays. Like other languages ruby also provides a set class that represents the mathematical notion of a set.

An enumerable object can be converted to set using the to set. Current implementation computes set intersection s1 s2 in o s2 size time. Set implements a collection of unordered values with no duplicates. You can check if one set is a superset of.

When a size and an optional default are sent an array is created with size copies of default take notice that all elements will reference the same object default. Set new 1 3 set new 2 5 set.